Forming machine

ABSTRACT

A shaping machine comprising an induction coil for inductive heating, in particular melting, of a material, and a body substantially surrounding the induction coil, wherein the body substantially radially and/or axially surrounding the induction coil is a magnetic and/or magnetizable body.

The present invention concerns a shaping machine in accordance with thefeatures of the classifying portion of claim 1. Shaping machines of thegeneral kind set forth include an induction coil for inductivelyheating, in particular melting of a material, a shaping cavity for theheated or molten material and a body substantially surrounding theinduction coil.

By way of example WO 2013/043156 A1 discloses such a shaping machine,wherein the body surrounding the induction coil is in the form of ashield which protects the environment from the electromagnetic radiationemitted by the induction coil.

A disadvantage with the structure disclosed there is that the shield isof a large and cumbersome structure and is heated by the currentsinduced by the electromagnetic field so that cooling is necessary. Theshields also disclosed in WO 2013/043156 A1 in the form of conductormeshes may be insignificant from the point of screening effectiveness atthe intensities and frequencies necessary for melting metal.

The object of the invention is to permit heating or melting of thematerial of a shaping machine with a higher level of efficiency and/orto at least not worsen the emission of electromagnetic waves outwardly.

That object is attained by a shaping machine having the features ofclaim 1. That is effected by the body substantially axially and/orradially surrounding the induction coil being a magnetic and/ormagnetizable body.

The term magnetizable bodies is used to mean those to which their own(temporary or sustained) magnetic moment can be imparted by applying amagnetic field.

By using a magnetic and/or magnetizable body the magnetic fieldgenerated by the induction coil is concentrated from the outset muchmore strongly on the near field and in particular on the interior of theinduction coil, wherein the technical effect pursued in WO 2013/043156A1 is automatically achieved. At the same time a higher electromagneticenergy density is produced within the induction coil by the concentratedmagnetic field whereby heating and/or melting of the material occurswith a higher level of effectiveness (that is to say higherelectromagnetic energy density within the induction coil with otherwiseidentical actuation of the induction coil).

Those components of the shaping machine which are arranged outside theinduction coil and the surrounding magnetic and/or magnetizable bodyalso experience lower levels of electromagnetic loading and thus lowerthermal loadings, by virtue of the invention.

The material to be heated and/or melted can be any conductor as currentscan be induced in those materials, which leads to the liberation ofheat. In particular the material can be a metal. The term “heating” isalso used to denote “melting”.

The heated and/or molten material can be put into the desired shape bymeans of the shaping cavity.

A (longitudinal) axis can be associated with the induction coil.

The statement that—for example—the body substantially axially surroundsthe induction coil can in particular be taken to mean that the bodysurrounds a notional, for example roughly cylindrically shapedperipheral surface of the induction coil over a large part (for examplemore than half, preferably more than three quarters and particularlypreferably completely). In other words the body is for a large part of aperipherally extending configuration in relation to the axis of theinduction coil.

The statement that—for example—the body substantially radially surroundsthe induction coil can be taken in particular to mean that the bodyoverlaps the induction coil in a view along the axis, wherein inparticular the overlap surrounds the axis for a large part (for examplemore than half, preferably more than three quarters and particularlypreferably completely). In other words the overlap can for a large partbe of a peripherally extending configuration around the axis.

By virtue of the invention it is also possible for the surroundingmagnetic and/or magnetizable body to be brought closer to the coil,whereby it is possible to achieve an overall smaller structure. Inparticular the spacing between the induction coil and the body can beless than a tenth, preferably less than a fiftieth and particularlypreferably less than a hundredth of the diameter of the induction coil.

A magnetic and/or magnetizable body substantially axially surroundingthe induction coil also affords an additional screening effect for thosecomponents which are arranged axially in the proximity of the inductioncoil and the surrounding body (see in that respect the example in FIG.5).

Further advantageous embodiments of the invention are defined in theappendant claims.

Particularly preferably there can be provided a shaping cavity for theheated and/or molten material. In other words, by introducing the heatedand/or molten material into the shaping cavity and then cooling it, inparticular hardening it, in the shaping cavity, it is possible to carryout a shaping process in the form of a casting process.

It can be provided that the magnetic and/or magnetizable bodysubstantially radially surrounding the induction coil at at least oneend of the induction coil—preferably at both ends of the inductioncoil—has an additional element which at least partially—preferablycompletely—overlaps the induction coil in a view along an axis of theinduction coil. Such an additional element deflects the magnetic fieldlines so that they also remain closer to the induction coil at the endsand thereby finally are also deflected inwardly. Besides the additionalconcentration function for the magnetic field this also affords anadditional shielding effect for those components which are arranged inthe proximity of the induction coil and the surrounding body (see inthat respect the example in FIG. 2).

It can be provided that the additional element at least partiallyoverlaps a central opening of the induction coil, which opening ispresent in the view along the axis. Just a relatively small overlap ofthe opening of the induction coil by the additional element can beuseful. In particular the minimum spacing which is to be maintained froma melting vessel to the surrounding body can be less than that spacingbetween the melting vessel and the induction coil.

It can particularly preferably be provided that the additional elementis in the form of an extension of the magnetic and/or magnetizable body.In other words the extension can embrace the induction coil at the end.

Because the additional element is an extension of the magnetic and/ormagnetizable body it is possible to prevent a gap being formed betweenthe main body of the magnetic and/or magnetizable body and theadditional element, which gap would weaken the concentration function ofthe body for the magnetic field.

Particularly preferably the additional element is in the form of aperipherally extending web which faces inwardly from the magnetic and/ormagnetizable body. That arrangement could also be identified as aninwardly facing flange on the magnetic and/or magnetizable body.

What applies for the additional element which is in the form of anextension, in relation to the magnetic and/or magnetizable body, alsoapplies generally to the magnetic or magnetizable body. In that sensethe magnetic and/or magnetizable body can be of a continuous or cohesivestructure, in which respect it can additionally be advantageous if thereare no holes in the magnetic or magnetizable body.

This does not prevent the magnetic and/or magnetizable body beingcapable of being of a multi-part structure. It is preferred in thatrespect however if either that is not the case or the individual partsof the magnetic and/or magnetizable body are in direct contact with eachother. Ultimately however the advantage of the invention can still beachieved to a certain degree even when the magnetic and/or magnetizablebody is not continuous and for example involves gap dimensions which donot exceed a tenth, preferably a fiftieth and particularly preferably ahundredth of the diameter of the magnetic and/or magnetizable body. Thatalso applies for any spacing between the main body of the magneticand/or magnetizable body and the additional element already referred tohereinbefore.

The magnetic and/or magnetizable body can include a ferromagnetic and/orparamagnetic material. The magnetic and/or magnetizable body can includemagnetic and/or magnetizable particles (for example ferromagnetic and/orparamagnetic) which are embedded in a non-magnetic matrix. That canserve to suppress induced currents within the magnetic and/ormagnetizable body. That effect however could also be achieved forexample with suitable layer structures within the magnetic and/ormagnetizable body.

The magnetic and/or magnetizable body substantially radially surroundingthe induction coil, in a particularly simple structure, can be of asubstantially cylindrical basic shape, which is possibly adjoined by theabove-mentioned additional element. The term cylindrical basic shape canbe used to mean for example a straight circular cylinder. Alternativebasic surfaces for the cylinder however are also certainly conceivable(oval, elliptical, square, hexagonal, generally polygonal).

The magnetic and/or magnetizable body substantially axially surroundingthe induction coil can be of a substantially disk-shaped—preferablyannular—basic shape. Instead of a circular disk it is also possible hereto use alternative basic surfaces (oval, elliptical, square, hexagonal,generally polygonal).

The induction coil can be substantially in the form of a helix (that isto say coiled screw-like).

Particularly preferably there can be provided a melting vessel separatefrom the shaping cavity for receiving the material to be heated and/ormelted, the induction coil being arranged at said melting vessel. In aparticularly preferred embodiment the melting vessel can be made from aceramic material (in one part or a plurality of parts).

Particularly preferably the induction coil substantially surrounds themelting vessel—preferably substantially radially.

A particularly simple structure is also conducive when the meltingvessel is of a substantially cylindrical configuration.

In a particularly simple embodiment the melting vessel, the inductioncoil and the magnetic and/or magnetizable body are arrangedconcentrically around a central axis.

Particularly in that case it can be provided that the melting vessel hasopenings oriented exclusively in the axial direction of the inductioncoil. On the one hand that in itself is a particularly simpleembodiment.

On the other hand there is a particularly preferred embodiment whenthere is a slider for pushing the heated and/or molten material out ofthe melting vessel into the shaping cavity, wherein the slider is thento be moved in the axial direction of the induction coil. A slider forpushing out the heated and/or molten material can however also beprovided in other arrangements of the melting vessel.

Further advantages and details of the invention will be apparent fromthe Figures and the related description. In the Figures:

FIG. 1 shows a sectional view of a shaping machine according to theinvention,

FIG. 2 shows the view of FIG. 1, with the magnetic field beingdisplayed,

FIG. 3 shows a further view illustrating the principle of the shapingmachine according to the invention with shaping cavity,

FIG. 4 shows a view of an embodiment according to the invention along anaxis of the induction coil, and

FIG. 5 shows an embodiment according to the invention, wherein the bodyaxially surrounds the induction coil.

In the embodiment of the invention shown in FIG. 1 it is possible to seefirstly the melting vessel 9, the induction coil 2 and the surroundingmagnetic and/or magnetizable body 5. They are oriented and arrangedconcentrically around a central axis X.

The directions along the axis X of the induction coil 2 are identifiedas axial and the directions perpendicular thereto are identified asradial.

In this embodiment the magnetic and/or magnetizable body 5 comprisesthree parts to simplify production. The material of the magnetic and/ormagnetizable body 5 is a non-magnetic matrix 8 in which magnetic and/ormagnetizable particles 7 are embedded (indicated in the drawing).

The magnetic and/or magnetizable particles 7 are shown as being ofcircular shape in the Figures for the sake of simplicity. In reality theparticles 7 are chip-shaped.

Disposed within the melting vessel 9 is the material 3 (in this case ametal) which was inductively heated and is now in a molten state.

The melting vessel 9 has exclusively openings facing in the direction ofthe axis X. A slider 11 can be guided through one of those openings(from the right in the view in FIG. 1), by means of which slider themolten material 3 can be pushed out towards the left. Disposed there isthe shaping cavity 4 (see FIG. 3), into which the molten material 3 ispushed under pressure. The material 3 is cooled in the shaping cavity 4in such a way that a crystalline solid body is substantially formed.

References 12 and 13 denote further parts of the shaping machine 1. Themelting vessel 9 is produced from a ceramic material to impart a highresistance to thermal loadings to the melting vessel 9. The furtherparts of the shaping machine 1 denoted by references 12 and 13 arehowever of a metallic material. The invention and in particular theadditional elements 6 in the form of extensions guide the magnetic fieldin such a way that the metallic parts 12 and 13 experience lowerelectromagnetic and thereby thermal loadings (in comparison with astructure without the additional elements 6).

In this respect attention is directed to FIG. 2 showing the sameembodiment as FIG. 1. In this case the references have been omitted forthe sake of simplicity, but magnetic field lines are now shown todisplay the magnetic field which occurs due to the magnetic and/ormagnetizable body 5 according to the invention. As already mentioned themagnetic and/or magnetizable body 5 guides the magnetic fields away fromany metallic attachments and concentrates the magnetic field (and thusnaturally also the electrical field) within the body and within theinduction coil 2, which also means: within the melting vessel 9. Thatconcentration of the electromagnetic field within the melting vessel 9affords a higher electromagnetic energy density at the location of thematerial 3 which is to be heated and/or melted, with the desired effectthat heating and/or melting takes place more effectively.

As already mentioned FIG. 3 shows a shaping machine 1 according to theinvention with the shaping cavity 4. The technical configuration of themelting vessel 9, the induction coil 2 and the magnetic and/ormagnetizable body 5 is similar to that of FIGS. 1 and 2.

The mode of operation is similar, this applying in particular also tothe slider 11.

FIG. 4 shows a view of the magnetic and/or magnetizable body 5 along thecentral axis X which is perpendicular to the plane of the drawing and isarranged in the center of the central opening. In this view the magneticand/or magnetizable body 5 appears annular. The induction coil 2 is alsoshown in dotted form, the induction coil 2 however being completelycovered (that is to say overlapped) by the additional element 6 of themagnetic and/or magnetizable body 5. That also applies for a small partof the central opening of the induction coil 2.

FIG. 5 shows an embodiment wherein the body 5 axially surrounds theinduction coil 2. As the displayed magnetic field lines show this alsoaffords a concentration of the magnetic field within the melting vessel9 and shielding in relation to external, axially arranged, furthercomponents, similarly to the embodiment of FIGS. 1 and 2.

It is pointed out the axis X does not necessarily have to be straight,that is to say it can also be curved. The geometries of the meltingvessel 9, the induction coil 2 and the magnetic and/or magnetizable bodycan then follow that curved geometry. Moreover however it is not evennecessary for for example the melting vessel 9 to be cylindrical.

1. A shaping machine comprising an induction coil for inductive heating,in particular melting, of a material, and a body substantiallysurrounding the induction coil, wherein the body substantially radiallyand/or axially surrounding the induction coil is a magnetic and/ormagnetizable body.
 2. The shaping machine as set forth in claim 1,wherein the magnetic and/or magnetizable body substantially radiallysurrounding the induction coil at at least one end of the inductioncoil—preferably at both ends of the induction coil—has an additionalelement which at least partially—preferably completely—overlaps theinduction coil in a view along an axis of the induction coil.
 3. Theshaping machine as set forth in claim 2, wherein the additional elementat least partially overlaps a central opening of the induction coil,which opening is present in the view along the axis.
 4. The shapingmachine as set forth in claim 2, wherein the additional element is inthe form of an extension of the magnetic and/or magnetizable body. 5.The shaping machine as set forth in claim 2, wherein the additionalelement is in the form of a peripherally extending web which facesinwardly from the magnetic and/or magnetizable body.
 6. The shapingmachine as set forth in claim 1 the magnetic and/or magnetizable bodyincludes a ferromagnetic and/or paramagnetic material.
 7. The shapingmachine as set forth in claim 1, wherein the body contains magneticand/or magnetizable particles embedded in a non-magnetic matrix.
 8. Theshaping machine as set forth in claim 1, wherein the magnetic and/ormagnetizable body is continuous.
 9. The shaping machine as set forth inclaim 1, wherein the magnetic and/or magnetizable body substantiallyradially surrounding the induction coil is of a substantiallycylindrical basic shape.
 10. The shaping machine as set forth in claim1, wherein the magnetic and/or magnetizable body substantially axiallysurrounding the induction coil is of a substantiallydisk-shaped—preferably annular—basic shape.
 11. The shaping machine asset forth in claim 1, wherein the induction coil is substantially in theform of a helix.
 12. The shaping machine as set forth in claim 1,wherein there is provided a melting vessel separate from the shapingcavity for receiving the material to be heated and/or melted, theinduction coil being arranged at said melting vessel.
 13. The shapingmachine as set forth in claim 12, wherein the induction coilsubstantially surrounds the melting vessel—preferably substantiallyradially surrounds same.
 14. The shaping machine as set forth in claim12, wherein the melting vessel is of a substantially cylindricalconfiguration.
 15. The shaping machine as set forth in claim 12, whereinthe melting vessel has openings oriented exclusively in the axialdirection of the induction coil.
 16. The shaping machine as set forth inclaim 12, wherein the melting vessel is made from a ceramicmaterial—preferably monolithically.
 17. The shaping machine as set forthin claim 12, wherein there is provided a slider for pushing the heatedand/or molten material out of the melting vessel into the shapingcavity, preferably being moveable in an axial direction of the inductioncoil.
 18. The shaping machine as set forth in claim 1, wherein there isprovided a shaping cavity for the heated and/or molten material.